Bank contact for telephone switches



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Patented on. 9, 1928.

1 UNITED STATES, PATENT OFFICE.

KURT BoHME, or nEiaLIN-sInMENss'rAn'r, GERMANY, AND KARL GIESE, or NowA- V was, NEAR GERMANY, ASSIGNORS TO SIEMENS & HALSKE AKTIENGESELLSCHAFT WERNERWERK, F SIEMENSSTADT BEI BERLI GERMANY. v

BANK CONTACT FOR TELEPHONE SWITCHES.

Application filed November 25, "1922. Serial naeoarzo and in Germany March 12,1921.

This invention relates to the bank contacts of switches used in telephone systems more particularly to those made up of separate strips in switches having the contactstrips located atright angles to the direction of rotation of the switchlwipers. Y

. The object of the invention is to facilitate the process of assembling and dismountlng the bank contacts at the switch racks, and

more particularly toenable the individual strips of contacts to be easily replaced with out disturbing the operation. The invention furthermore; enables several switches to be compactly located above-one another.

According tothe inventiona contact bank is formed of'contact strips that are connected with the switch rack, by fastening means provided partly at the switch rack and partly at the conta'ct strips. The. strips forming the contact bank are preferably connected to the switch rack by means of a fastening, which can be closed by pushing one part into the otherin a radial or oblique direction with respect to' the switch shaft. The strips of bank contacts can be secured in. place by" a fastening which embraces these strips at.

their end surfaces located parallelto the switch shaft; The fastening can comprise a band provided at intervals with fixing the strips of bank contacts. The hiring means provided at each strip-0f bankkcon-v tacts are preferably interconnected by metal plate, which also acts as a stiffening piece. Y

According to the invention the switch rack can be provided with cylindrically shaped holding members having slots, into which fits sideways extension pieces at the upper and lower ends of the'jc'cntact strips. The slots engaged by one end of the contact strips are of sufficient length to allow the ends of. the contact strips to move freely therein in a' longitudinal direction. r The drawing shows one method'of carrying out the invention.

' Figure 1 shows an elevation and Figure 2- plan view of the contact bank. Figure 3 shows aside elevation andFigure 4 aplan view 'of a single contact strip.

rails a and interconnecting pieces The lat-- ter take the'form of a segment and their means that engage corresponding means in The switch rack is composed of upright vertical slots (2,03 into which fit the tongues c, e of the, contact strips f. These tongues and slots are so shapedin the example 'illus-. trated, that they can be pushed into one another in a. direction, which is radial with respect to the switch shaft. They could however be so shaped that they can be pushed into one another obliquely to the switch snaft.

It willbe seen from Figure 2 that the contact strips f, are mounted fanwis e at regular intervals to the flanges c, 0 by inserting the tongues e, 6 into. the slots d, (1 Each con tact strip f comprises a row of contacts g, around which is pressed rectangularly shaped insulating material through which the ends of the ,contactsextend at both sides. The

two tongues e, e projecting at top and bottom of. the strips'comprise the legs of a Ufshaped plate h which is covered with the insulating material. This plate extends through .holes 0 .(Figure 4) in the contacts 9 and serves to stiffen the contactjstrip 1 The metal plate 72. also serves as an earth plate for conducting away currents which might occasion cross talk. 1

In order to enable the strip 7 to be easily replaced the slots d of one of the flanges .0 are made long enough to allow the corresponding tongues e to have sufficient play inthe longitudinal direction. Each contact strip has a notch i at its. outer end surface which is parallel to the selector shaft. A

fmetal band an fastened to the. selector frame has projectionsk at regular intervals. When a strip f is mounted on the switch rack, its

notch engages a projection'k. This ensures that the strips retain their correct fan shaped location on the rack. Alternately the strips f could be provided with pins to engage cor responding holes in the metal band m.

The metal band m is adapted to be easily removed from the rack. For this purpose itis provided with slots, which engage with rivets or pins 9 on flanges r on the rack. After'the band at has been removed, it is thereforel'possible to quickly removeand re-.

place the individual contact stripsf as required without having to, loosen a screw.

The band m could, however be secured to the rack by means of screws or in any other manner desired.

What we claim and desire to protect by Letters Patent is v l. The combination, in a contact bank for-a telephone switch, of a pro-assembled switch rack, a plurality of separate contact strips, and means for mounting said contact strips on upper and lower portions of said .prer' assembled switch rack to forma complete contact bank, while maintaining the upper and lower portions of the rack intact, and a single element for holding. all the contact strips in place on said rack.

2. The combination, in a contact bank for a telephone switch, of a pro-assembled switch rack having two horizontal members, a plurality of flat contact strips, and means including the horizontal members of the switch" rack and a band secured at two points to said rack and encircling said contact strips for supporting said strips sidewise in fixed relation to said switch rack.

3. The combination, in a contact bank for a telephone switch, of two substantially parallel curved supporting members having perforations therein, a plurality of separate,

contact strips each having two lugs, the lugs of each strip adapted to enter radially perforationsin the curved members, respectively, notches in the outer edges of said contact strips, an encircling band secured tothe switchrack at two points and passing around the outside edges of all the contact strips, and notches in said band cooperating with the notches in the outside edges of said strips to hold said contact strips in fixed space relation to each other.

, 4. The combination, in a contact bank for a telephone switch, of a support, having a pair of horizontal bars in permanent fixed r ation toeach other, a plurality of flat contact trips mounted on the bars of said support while maintaining the bars intact, and means on the bars of said support and on said strips including lugs in one case and cooperating mortises in the other case for substantiall reventin sidewise and endwise movement of said contact strips with respect to the support.

5. The combination, of a pie-assembled semi-circular telephone switch rack, and a plurality of vertically arranged separate contact strips each comprising a plurality of contacts and adapted to be moved in a radial direction into position on said switch rack to form a complete contact bank.

.6. A bank contact assembly comprising a plurality of perforated individual contacts arranged in a row one above the other and embedded in insulating material, and a metallic stiffening members passing through the perforations in the contacts. I

7. The combination, in a contact bank for a telephone switch, of a support, a plurality of flat contact strips mounted on said supports, means on said support and on said strips including lugs in one case and cooperating mortises in the other case for substantially preventing side-wise and endwise movement of said contact strips with respect to the support, and a semi-circular band secured at either end passing around the outer edges ofthe contact strips to maintain them tight up against the support.

8. The combination, in a contact bank for a telephone switch, of a support, a plurality of flat contact strips mounted on said support, means on said support and on said strips including lugs in one case and costrips including lugs in one case and cooperating mortises in theother case for substantially preventing side-wise and endwise movement of said contact strips with respect to the support, and a semi-circular band secured at either end passing around the outer edges of the contact strips to maintain them tight up against the support and to maintain them in fixed space relation to each other.

10. A bank contact assembly comprising I a plurality of individualcontacts arranged v in arow one above the other andembedded in insulating material, and a metallic member embedded insaid material in a right angle to said contacts and provided with lugs extending from the member in a right 'anglein a plane parallel to the contact element-s. I g r 11. In an automatlc swltch structure, a support, banks of contacts having lugs enter- .in'g openings in said support, and means located back of said contact banks and mldway between the upper and lower ends thereof for firmly holding said banks in fixed relation to said support.

12. A contact assembly comprising aplurality of individual contacts arranged one above the other and embedded in a block of insulating material, the ends of said contacts projecting through opposite surfaces of said block, and two mechanically inter-connected lugs also embedded in said block and projecting through one surface through which said contacts project, one lug projecting above the contacts, the other lug projecting beneath the contacts.

13. A bank contact assembly comprising a plurality of perforated individual contacts Signed by me at Berlin, Germany, this 28th day of October, 1922.

' KURT BOHME.

KARL GIESE.

arranged in a row one above the other, a metallic stiffening member passing through the perforations in said contacts, projecting lugs on said member, one ateither end of said assembly, said contacts, member and projecting lugs all embedded in insulating material. 1 

